It seems wrong to be planning for winter now, but it's a must if you want fresh greens later on. Those summer salads, all soft and sweet, won't last much longer. A month, maybe two, and they'll whimper and give up. Come autumn, you need a different salad, the sort that loves the rough and laughs in the face of smooth leaves. I'm talking about oriental greens: mizuna, mibuna, pak choi, leaf radish and mustards.

Sow little and often from now until early autumn, to give you a supply that, with a little protection (fleece or cloches), will take you through to spring. These greens need warm temperatures in the early stages of growth. If they don't get this heat, they head straight to flowering, so you can't sow much past the end of September.

The best way to raise them is in modules. This alleviates any space problems, allows you to raise healthy stock with good roots and lets you keep on top of how much you've sown. This is important, particularly with pak choi, which are often F1 hybrids bred to mature at the same time. As much as I love to eat them, there is little anyone can do with 30 pak choi in one week.

So, what to sow? I don't have much time for mixed salad packets of oriental greens, often called "spicy mix". I find the pak choi gets stressed and bolts, the mustards compete with the mizunas and you get a lot of tough, hot leaves. Either prick out individual species or buy separate packets. Space plants 20-25cm apart for medium-sized leaves, or 10cm for baby leaves.

The spiky mizuna is the easiest to grow, but will get spicier with age and size. The trick is to cut regularly. Keep cutting until the leaves become too tough. The paddle-shaped mibuna has milder-tasting leaves and is slower growing. Cut the first flush of leaves within one month of sowing. The mustards can be very hot. 'Golden Streak', 'Ruby Streak' and 'Red Frills' are pretty and less hot, but are often the first to go to flower. 'Green in Snow' is the hardiest mustard, standing in a blanket of white, but, boy, is it hot to eat. Come midwinter, these are best for stir-fries or finely shredded for a spicy garnish.

I like 'Green Revolution' F1 or 'Joi Choi' for a classic pak choi, but both need protection (cloche or fleece). Use the baby leaves for salad, and harvest a few leaves at a time. If they go to flower, eat them. My favourite leaf radish is 'Red Stemmed'. If you cut it two weeks after sowing, it will re-sprout for further harvests. Eat it young though or it will get tough. If you miss the moment, steam it instead.

Alys on... hoverflies

Photograph: Alamy

Hoverfly larvae are pretty gross, which is a shame because I bet a lot have been squished for this reason. They look like maggots and spend the day hiding in the crooks of leaves, feeding mostly through the night. They are voracious eaters and their favourite meal is aphids. They can eat several hundred in their short adolescence. The pupae is pear-shaped and fixed to the plant. After just a couple of days, they emerge as adults.

The adults mimic bees and wasps, wearing their stripy warning colours as a defence, but, being true flies (just one set of wings), have no sting. The adults are vegetarian, eating mainly nectar and pollen. The female needs large amounts of pollen to mature her eggs, which she lays even amoung low aphid densities all summer long. This makes her something of a super-predator, because she doesn't need the pest problem to get huge before she moves in.

They can keep on top of aphid problems if plenty of flowers are about. Pollen and nectar-rich plants such as umbels (coriander, caraway, angelica), poached egg plants (Limnanthes douglasii), Phacelia tanacetifolia and buckwheat increase the adult fly population and thus their aphid-munching babies.